Natural History Notes 49 Holbrookia Lacerata (Spot-tailed Earless Lizard) Predation

Authors: Danielle K. Walkup, Connor S. Adams, Wade A. Ryberg, Toby J. Hibbitts

Full text originally published in the Herpetological Review 49(4). Natural History Notes.

HOLBROOKIA LACERATA (Spot-tailed Earless Lizard)

Holbrookia lacerata is a small phrynosomatid lizard found in short-grass plains from south and central Texas into northern Mexico (Hibbitts and Hibbitts 2015. Texas Lizards: A Field Guide. University of Texas Press, Austin, Texas. 333 pp.).

They are a cryptic, easily startled lizard that has been little studied (Axtell 1956 Bull. Chicago Acad. Sci. 10:163–179). Here we report the first record of H. lacerata as prey for Hypsiglena jani. During telemetry fieldwork on H. lacerata, the radio signal of an individual was located at the corner of an oil-well pad at 0900 h on 28 June 2017, approximately 63 m northwest of the prior fix at 1312 h on 27 June 2017. The signal was coming from a large pile of rocks, atypical habitat for H. lacerata. Careful removal of the top layer of rocks exposed an adult H. jani, with a distended stomach. We palpated the snake, which regurgitated the H. lacerata with the radio still attached (Fig. 1). At the initial capture of the lizard on 26 June 2017, before attaching the radio, mass was 4.8 g, SVL was 54 mm, and tail length was 42 mm. After regurgitation, prey mass = 4.3 g, SVL = 59.5 mm, and tail length = 40.4 mm. The H. jani measured 17.3 g, SVL = 279 mm, and tail length = 50 mm. Prey to predator weight ratio was 27.7%, and total length ratio was 29.2%.

Hypsiglena jani is a known predator of many lizard species, and phrynosomatid lizards appear to comprise a large proportion of their diet (Rodr.guez-Robles et al. 1999. Copeia 1999:93–100). Consistent with previously reported H. jani predation activity, the snake swallowed the lizard head-first. The radio, which was attached mid-dorsal with the radio antenna extending posteriorly, along and past the tail of the lizard, did not appear to hinder swallowing. Both specimens were collected and deposited in the Biodiversity, Research and Teaching Collections at Texas A&M University, College Station as H. jani: TCWC 103603 and H. lacerata: TCWC 103604. Both specimens collected under the authority of a Texas Parks Wildlife Department scientific permit [SPR-0506-662].